TWI470871B - Antenna device - Google Patents

Description

Antenna device

The present invention relates to antenna devices, and more particularly to antenna devices primarily used on base stations.

Usually, the base station antenna is placed at a high place, and data transmission and reception are performed between the fixed communication terminal or the mobile communication terminal by the radio wave radiated from the antenna.

Such a base station antenna is required to form a beam pattern by radiating electric waves to a fixed area in the ground direction. Therefore, the base station antenna is configured as an array antenna in which the antenna elements are arranged in the vertical direction. Further, the base station antenna having such a configuration has a power supply circuit for supplying a predetermined amplitude ‧ phase to each antenna element so that each antenna element obtains a predetermined beam pattern.

In general, the beam pattern of such a base station antenna forms a beam width of about 6 degrees on the vertical plane and a beam width of 60 to 180 degrees in the horizontal plane. Further, the beam width of about 6 degrees is formed on the vertical surface and the desired gain is obtained, and the number of components of about 12 to 14 elements is used as the antenna element. Further, in such a base station antenna, a reflector made of a metal plate is used on the back surface of the antenna element to form a beam width in the horizontal direction.

Moreover, the polarized wave of such a base station antenna is usually a 2-port antenna having two polarized waves including vertically polarized waves, horizontally polarized waves, or horizontally polarized waves and vertically polarized waves; or 2-port antenna with 2 polarized waves of 45 degrees and -45 degrees.

Moreover, such a base station antenna is usually a structure covered with a radome made of FRP (Fiber Reinforced Plastics) or PVC (polyvinyl chloride), as a structure resistant to an outdoor environment. .

An example of such an antenna covered by a radome is described in Patent Document 1. The planar antenna described in Patent Document 1 constitutes a hermetic container by a metal shield plate and a radome. In response to this, due to the structure forming a hermetic structure, temperature changes inside and outside the planar antenna cause air expansion and contraction in the planar antenna, resulting in a difference in air pressure between the inside and outside of the planar antenna. Further, although the air pressure difference between the inside and the outside of the planar antenna is uniformly applied to the metal shield plate and the radome, the radome is generally less rigid than the metal shield plate and is thus deformed. Therefore, the planar antenna described in Patent Document 1 is provided with a circular hole to prevent deformation of the radome due to pressure change and temperature change inside and outside the planar antenna.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Publication No. 05-145317

The above example shows a base station antenna for outdoor use for communication, and is usually constructed by covering a radome made of FRP or PVC material to withstand an outdoor environment. Therefore, since it has a hermetic structure, it has a tendency to become large in shape and to increase in weight. For example, the planar antenna described in Patent Document 1 can be configured to cover the air pressure and the temperature by providing a circular hole. However, the planar antenna has a structure in which the antenna cover is covered, so that the outer shape is increased and the weight is increased.

Further, the base station antenna has a structure in which a reflector made of a metal material is provided on the back surface of the antenna element, and a predetermined beam width is obtained in the horizontal direction. However, since it is necessary to have an area of the size of the reflector, the weight tends to increase.

The above-mentioned base station antenna is usually placed at an outdoor tower or a high place on the building, and therefore it is required to have an installation strength that does not cause the antenna to rotate due to the weight of the antenna and strong wind.

Moreover, when the weight of the antenna is increased, it also becomes a factor for setting the workability to deteriorate.

Therefore, the exemplary object of the present invention is to provide an antenna device which is relatively simple in construction and small in size and lightweight, and a wireless communication device using the antenna device.

An embodiment of the present invention provides an antenna device comprising: a plurality of antenna elements; a power supply circuit for supplying power to the plurality of antenna elements; and a conductive frame accommodating the plurality of antenna elements and the power supply circuit therein And a plurality of openings, each of which faces the plurality of antenna elements; and a thin plate-shaped mask covering the plurality of openings of the conductive frame, and sealing the plurality of openings.

According to the present invention, it is possible to realize a small-sized and thin structure, and it is possible to realize a small-sized and lightweight structure antenna without requiring an antenna radome structure.

(Best form of implementing the invention)

First, an outline of an exemplary embodiment of the present invention will be described. In an exemplary embodiment of the present invention, the antenna accommodates a plurality of array antenna elements and a power supply circuit for supplying a predetermined amplitude ‧ phase to the antenna element in the conductive housing, and the conductive frame has a plurality of openings, respectively facing the plurality of antennas element. Further, the structure in which a large number of openings are sealed by a thin plate-shaped mask or the entire conductive frame body is sealed by a thin plate-shaped mask. The conductive frame and the thin plate-shaped mask function as a reflector and a radome of the antenna device. As the antenna element, for example, a panel antenna can be employed. With such a configuration, the antenna device of the present embodiment has a structure that is small and particularly thin, and has a structure in which the antenna radome is not required. Therefore, an antenna of a small size and a lightweight structure can be realized.

Next, an exemplary embodiment of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a perspective view of an antenna apparatus according to an embodiment of the present invention.

As shown in Fig. 1, the antenna device of the present embodiment includes a plate-shaped metal casing 11, a thin plate-shaped mask 12, a plurality of antenna elements 13, and a power supply circuit. Here, the antenna elements are shown by setting 13 examples, and are not limited to this number. However, when the antenna element is used as a base station antenna as described above, the number of elements of about 12 to 14 elements is used. The thin plate-shaped mask 12 can be attached with a resin such as polyvinyl chloride (PVC).

The antenna element 13 and the power supply circuit are built in a rectangular sheet metal chassis 11 that serves as a conductive frame. In addition, the illustration of the power supply circuit is omitted in FIG. Furthermore, the details of the power supply circuit will be described later. The plate-shaped metal casing 11 is provided with a plurality of openings, and the plurality of openings are opposed to the plurality of antenna elements 13, respectively. That is, the top surface of the plurality of antenna elements 13 has an open configuration. Furthermore, the antenna device of the present embodiment has a structure in which a large number of openings of the plate-shaped metal casing 11 are covered by a thin plate-shaped mask 12, and a plurality of openings are sealed. In the present embodiment, the plate-shaped metal frame 11 made of a metal plate is used as the conductive frame. However, a conductive layer may be formed on an insulating plate such as plastic or a conductive plastic may be used as the conductive frame. The both ends of the plate-shaped metal casing 11 in the longitudinal direction are not substantially opened, but one end or both ends may be opened as necessary. The shape of the plate-shaped metal frame is here a small, lightweight, advantageous rectangular shape, but not necessarily rectangular.

Figure 2 is a cross-sectional view showing the internal structure of the antenna device of Figure 1. Fig. 3 is a perspective view showing the internal structure of the antenna device of Fig. 1. In FIG. 3, the thin plate-shaped mask 12 is omitted, and the internal printed circuit board 15, the power supply circuits 17, 18, and the antenna element 16 are shown by solid lines.

Fig. 4 is a perspective view showing a partial display of a printed substrate and a plate-shaped metal frame. Figure 5 is a partial enlarged view of the printed substrate of Figure 4.

Referring to FIGS. 2 to 5, the antenna device of the present embodiment has a printed circuit board 15 in a rectangular plate-shaped metal casing 11. The printed circuit board 15 has power supply circuits 17 and 18 and antenna elements 16 which will be described later, and the antenna element 13 is connected to the antenna element 16 via a central pole 14 which serves as a conductive column. Further, as described above, the plate-shaped metal casing 11 has an open structure on the antenna element 13, and has a structure in which a large number of openings of the plate-shaped metal casing 11 are covered by the thin plate-shaped mask 12.

As shown in FIGS. 3 to 5, the printed circuit board 15 has a power supply circuit (the power supply circuit 17 and the power supply circuit 18), and the power supply circuit supplies power from the power supply position 19 or the power supply position 20.

Next, the operation of the antenna apparatus of this embodiment described with reference to Figs. 1 to 5 will be described.

In the antenna device of the present embodiment, power is supplied from the power supply position 19 on the power supply circuit 17 and the power supply position 20 on the power supply circuit 18 which are formed on the printed circuit board 15, and the power is supplied. Then, the supplied electric power is distributed to a predetermined power and amplitude by the power supply circuit 17 and the power supply circuit 18, and is supplied to the antenna element 13 and the antenna element 16 which are formed on the printed circuit board 15, respectively. A coaxial cable is connected to the power supply position 19 and the power supply position 20, respectively, and power is supplied via the coaxial cable. It is also possible to mount a connector on the printed substrate 15 and supply power via the connector. The coaxial cable can be taken out by providing an opening portion of the plate-shaped metal casing 11 that can take out the size of the coaxial cable.

The antenna element 16 and the antenna element 13 are connected by a central pole 14 to reach a wide frequency band of the antenna. However, the antenna element 13 and the central pole 14 may not be provided, and only the antenna element 16 may be provided. At this time, the plate-shaped metal casing 11 has a plurality of openings, and the plurality of openings face the plurality of antenna elements 16 respectively.

A plurality of antenna elements 16 and a plurality of antenna elements 13 are arranged at predetermined intervals, and a predetermined beam pattern in the vertical direction is formed by the amplitude ‧ phase of the power supply circuit 17 and the power supply circuit 18.

The beam width in the horizontal direction is determined by the width of the plate-shaped metal casing 11 and the characteristics of the panel antenna composed of the antenna element 13 and the antenna element 16. Further, for example, a beam width of about 65 degrees is set.

Here, the power supply circuit 17 radiates horizontally polarized waves in the present antenna device by supplying power to the antenna element 16 from the horizontal (horizontal) direction. On the other hand, the power supply circuit 18 supplies power from the vertical (longitudinal) direction of the antenna element 6 and radiates vertically polarized waves in the present antenna device. The power supply circuit 17 corresponds to the second power supply circuit, and the power supply circuit 18 corresponds to the first power supply circuit.

The plate-shaped metal casing 11 is provided with an opening for radiating radio waves of the antenna device. The thin plate-shaped mask 12 blocks the opening of the plate-shaped metal casing 11, and the inside of the antenna of the antenna device is sealed.

Next, another embodiment of the present invention will be described with reference to Fig. 6 .

In the antenna device of FIGS. 1 to 5, the thin plate-shaped mask 12 is covered so as to block the opening of the plate-shaped metal casing 11, but the structure of the antenna device shown in FIG. 6 is covered by the mask 21. The plate-shaped metal casing 11 as a whole. The antenna device shown in Fig. 6 is more airtight than the antenna device of Figs. 1 to 5, and a heat shrinkable sleeve made of, for example, a polyolefin resin can be used as the mask 21.

In the above embodiment, a spherical antenna is used as the shape of the antenna element 13 and the antenna element 16, but they are all shown by way of example. A square antenna element can also be used as the antenna element 13 and the antenna element 16.

Further, in the antenna apparatus of the present embodiment, vertical polarized waves and horizontally polarized waves are simultaneously used as an example, but this is an example. It can also be used as an antenna device using only one of a vertically polarized wave or a horizontally polarized wave by using one of the power supply circuit 17 or the power supply circuit 18. It is also possible to provide only one of the power supply circuits 18 of the power supply circuit 17 on the printed substrate 15. Further, it is also possible to change the power supply position of the antenna element 16 as an antenna of +45 degrees and -45 degrees of polarized waves.

As described above, the antenna device of the present embodiment has a structure in which a plurality of antenna elements are housed inside the plate-shaped metal casing and a power supply circuit for supplying a predetermined amplitude ‧ phase to the antenna element, and the plate-shaped metal casing The antenna element has an opening above it. In addition, the structure in which the opening portion is sealed by the thin plate-shaped mask or the entire plate-shaped metal frame is sealed by the thin plate-shaped mask, and the plate-shaped metal frame and the thin plate-shaped mask have the antenna reflection plate. And the construction of the radome function. Further, by using a planar antenna as an antenna element, the present antenna is advantageous in a small and particularly thin structure, and it is a structure that does not require a general antenna radome, and can realize a small-sized and lightweight structure. In the thin plate-shaped mask of the antenna device of FIGS. 1 to 5, the periphery of the portion of the plate-shaped metal casing 11 may be covered with a heat shrinkable sleeve to block the opening of the plate-shaped metal casing 11. Further, in the thin plate mask of the antenna device of Fig. 6, the entire plate-shaped metal casing 11 can be covered with a resin tape.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention. Therefore, the foregoing embodiments are merely illustrative and should not be construed as limiting. The scope of the present invention is shown by the scope of the claims, and is not limited by the description and the abstract. Further, variations or modifications of the equivalent scope of the claims are intended to be within the scope of the invention. Further, the present invention is not limited to a specific communication method or device, and can be applied to various communication methods and devices.

This case claims priority based on the Japanese Patent Application No. 2009-194240 filed on August 25, 2009. In addition, the entire disclosure of the Japanese Patent Application No. 2009-194240 is cited.

11‧‧‧Sheet metal frame

12‧‧‧Thin-plate mask

13‧‧‧Antenna components

14‧‧‧Central pole

15‧‧‧Printing substrate

16‧‧‧Antenna components

17‧‧‧Power supply circuit

18‧‧‧Power supply circuit

19‧‧‧Power supply location

20‧‧‧Power supply location

21‧‧‧ mask

Fig. 1 is a perspective view showing an embodiment of an antenna apparatus according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view showing the internal structure of the antenna device shown in Fig. 1.

Fig. 3 is a perspective view showing the internal structure of the antenna device shown in Fig. 1.

4 is a perspective view showing a part of a printed substrate and a plate-shaped metal frame.

Figure 5 is a partial enlarged view of the printed substrate of Figure 4.

Fig. 6 is a view showing an aspect of an antenna according to a second embodiment of the present invention.

11. . . Plate metal frame

12. . . Thin plate mask

13. . . Antenna component

Claims (10)

An antenna device comprising: a plurality of antenna elements; a power supply circuit for supplying power to the plurality of antenna elements; and a conductive frame body accommodating the plurality of antenna elements and the power supply circuit, and having a plurality of openings, the plurality of opening portions And the plurality of openings of the conductive frame are covered, and the plurality of openings are sealed; wherein the plurality of antenna elements include a plurality of first antenna elements and a plurality of antenna elements In the second antenna element, the plurality of first antenna elements are respectively connected to the plurality of second antenna elements via a plurality of via electrodes, and the plurality of openings are provided to face the plurality of first antenna elements, respectively. The plurality of second antenna elements, the plurality of first antenna elements, and the plurality of openings are provided in this order. The antenna device of claim 1, wherein the thin plate-shaped cover covers the entire conductive frame. The antenna device of claim 1 or 2, wherein the plurality of antenna elements are planar antennas. The antenna device according to claim 1 or 2, wherein the power supply circuit has at least one of a first power supply circuit for a first polarization wave and a second power supply circuit for a second polarization wave. The antenna device of claim 4, wherein the first polarized wave is a vertically polarized wave, and the second polarized wave is a horizontally polarized wave. The antenna device according to claim 1, wherein the power supply circuit and the plurality of second antenna elements are formed on a circuit board. The antenna device of claim 1, wherein the thin plate-shaped mask is a resin tape or a heat shrinkable sleeve. The antenna device of claim 1, wherein the material of the thin plate-shaped mask is made of polyvinyl chloride or polyolefin. The antenna device of claim 1 or 2, wherein the conductive frame system is one of: a metal plate, a conductive plastic, or an insulating plate having a conductive layer formed on the surface. The antenna device of claim 1, wherein the conductive electrode columns are central poles of the respective antenna elements.